Overflow control for filter beds



July 6, 1948. L. 1... SMITH OVERFI IOW CONTROL FOR FI LTEB BEDS 2 S heets- Sheet 1 Filed March 30, 1945 y 6, 8 v 1.... L. SMITH 2,444,682

OVERFLOW CONTROL FOR FILTER BEDS Filed March so, 1945 I 2 fleas-mun 2 Patented July 6, 1948 UNITED-= I PATENT OFFICE 2;444,cs2, mmowiemmot Eon FmtnnnBnns, Luther 1;. smtawma Robins, Ga. Application time, 1945; Serial No. 585,593:v 'aclaims, (crzio t),

This invention appertains. to overflow controls forrfllter .beds of sewage treatment plants, andhas for, one of its several. objects to provide a systemaccordance with changes in directionv of winds, blowing across the surface of the bed; ,itzhaving,

beenascertained that, when a Water-,level-is established above the bed surfacexthe larvae loosens from the bed rock and rises tothesurface of;the water and, when floating thereon, collects v at the side of the filter-bed, in the direction of blow of thewind. i t

With the foregoing andother objects and-,ad-w vantagesin View, the, invention resides in the cer,-, tain new and useful combination,,,construction; and arrangement of parts, as will be hereinafter more'fully described, set forth in-the appended; claims, and'illustratedin the accompanying draw.- ings, in which: H

Figure 1 is a top plan view of a trickling filter, bed, showing the system of overflow controls therefor, in accordance with the invention;

Figure2 is a vertical section, taken through the line 2-2 on Figure 1, looking in the direction-ofthe arrows;

Figure 3 is an enlarged, fragmentary, top;plang view of one of the overfiowwells and the wei-rgatecontrol therefor;

Figure 4 is an enlarged, fragmentary, vertical section, taken through the linel -4 on Figure 3, looking in the direction of. the arrows;

Figure 5 is a sectional view similar to that of, Figure 4, but taken through the line 55"on Figure 3, looking in the direction ofthe arrows;

Figure 6 is another enlarged,-,fragmentary,.yertical section, taken through the line 6-6,-on,Ffigure, 1, looking in the directionof the arrows;

Figure 7 is a sectional view similar to that of Figure 6, but taken through theline 1--"l on Figure 1, looking in the direction of the arrows; and

Figure Sis an enlarged fragmentof the vertical section of Figure 4 taken on the same line as that of Figure l, showing the spillway through the side wall:v of the filter bed tank and the weir gate therefor, the spillway leading from the surface of the filter bed and sloping downwardly therefrom into: an overflow well illustrating a modification, wherein the lower surface of the well is at a higher elevation than that of the well shown in Fig. 4.

Referring in detail to: the drawings, wherein like characters of reference denote corresponding parts. in the several views, the invention, ,as. it is. exemplified, therein, is'applied to a more or less conventional type of trickling filter bed for the treatment of,sewagawhichismade up of a cylinl2, supporting a bed.;of-crushed rock l4, filling the tank'to .-a level short-ofthe top-edge of-its side the layer of filter blocks 12, substantially as shown;

inllig-uresland 2:. A- pipe line-22 leads fromthe well L6,,at the frontside of the tank l-li,toco1;1vey-=v thefiltered liquidto apoint for further treatment, such as the flnal clarification thereof. 7

In carrying out-the invention, the two, main wells I16. and I8 arelmodified, respectively, bythe formation of auxiliary overflow wells-or'catch basins 2 4 andv 26.-;within the upper open end-portions thereof, eachof which has a horizontal, area substantially one-half of that of a main Well, with its bottomlocated, in ahorizontal; plane ashort, distance' belowthe level of the rock bed, I 2:. The innenvertical, side walls of the overflowwells Z l-and-ZS, forming the divisionsbetweenthe same and the main wells I6 and I8,,have their top, edges located belowthose of the outer side Walls and: sloped to provide spillways, for the:overfiow of liq: uid from the main wells; the spillways having weir gates-2,8. and 30- to control the overflow of liquid into the auxiliary wells-24 and- 26, respec, tively, Qpen-ingthrough the bottornof the auxiliaryoverfiow well His a drainage pipe 32-, leadto and-connectingthe pipe line 22; Formed inthetop-edge-of the side wall of the tank t0; are spillwaysgs l which slope downwardly into the auxiliary overflow wells M-and zfi, fromthe levelgof the rock bed I 2, and are provided with, weirgates 36-and.38, .respectively.

Formed ,on the outer side of the sidewall of the. tank: lll are other overflow wells lttandg ld, which, are disposed at opposite sides: of the tank and spaced; equidistantly from the auxiliary over flowwells: ,24 and 26,- and have spillways opening into the; samethrough the side wall of the :tank; with weir gates M and;4-6, respectively, to control the flow of liquid, from the tank, above the level of the rock bed it. A drainage outlet 48 isformed in, the bottom: of each-.of'the overflow wells 26, 4D, and 4 2, and those of the overflow wells 26- and-i412 are connected with, a common pipe line 58lead-ing co-and connecting the pipe line 22 as. at 52, outwardly fi'omthe point of connection of the drainage outlet pipe 32 therewith, while the outlet fromlthe overflow welll lll,

has connection with a pipe line 54, leading to and connecting the pipe-line 2.2:,commonly with the pipe line 501, A cutoif valve 56, is interposeddn, the pipeline- 50, between the outlets from the overflow Wellslliwand A2; aisecond cutoff, valve nection 52. As best shown in Figure 8, each of r the weir gates is mounted for vertical sliding movements in metal channels 62 secured in the sides of the spillway openings, in the side wall of the tank i0, and are provided with hand grip openings 64 in portions of the same projecting above the top of the tank wall.

gate and below the upper edge of the basin, gates in said weirs, catch basins communicating with said weirs, a shear gate in the well at the lower end of said drainage channel, a discharge connection leading from the shear gate, and overflow connections from the catch basins to said discharge connection.

In operation, with the shear-gate 10 at the outlet end of the drainage pipe line 22 within the main well 96 open, and the several cutoff valves 56, 58, and 60, together with the weir gates 28, 30, 36, 38, Ml, and 45, closed, the sewage treating plant will operate in the usual manner, briefly as follows: Sewage from a primary clarifier (not shown) passes to and through a dosing tank (not shown) to a spray head (not shown). This spray head is mounted to rotate ona pedestal B5, rising from the bottom of a well 68, formed centrally within the tank Hi, and has a plurality of radiallyextending, hollow, perforated arms, to distribute the partially clarified liquid evenly over the surface of the rock bed 34; the liquid trickling downwardly through the latter and onto the filter blocks l2, from whence it passes to the drain channel 20 and outwardly from the main well l6, through the pipe line 22 to a secondary, or final, clarifier (not shown).

In warm weather, particularly in the summertime, filter flies deposit their larvae within the crevices of the rock bed l4 and, unless destroyed, will rapidly develope to reproduce their kind. In order to rid the rock bed 14 of the larvae, the shear gate 18- is closed and the liquid is allowed to fill the tank H), to a level above the surface of the rock bed. With the rise of the liquid within the tank to such level, the larvae loosens from the crevices in the rock bed Hi and floats on the surface of the liquid, and will accumulate at a side of the tank, in the direction of the blowing of the wind. After an elapse in time suflicient to assure of the flotation of the larvae on the surface of the liquid, the weir gate of an overflow well, at the lee side of the tank II], will be opened for the draining ofi of the surplus liquid and'its larvae content, through an outlet 48 and the drain pipe line connected therewith, upon the opening of one or more of the cutofi valves 58, 58, and 80.

Without further description, it is thought to be obvious that the invention provides a simple but highly eliective means for obliterating an otherwise serious menace to the health of a community where open filter beds are employed in the treatment of sewage; and it should be understood that, while I have described and illustrated my invention in specific terms and in detail, changes in design and minor details of construction may be resorted to, within the limits defined by the scope of the appended claims.

What I claim is:

1. In a trickling filter basin having a relatively large open shallow area adapted to hold a filter aggregate with the upper surface of the aggregate spaced from the upper edge of the basin, and having a false bottom with a centrally disposed drainage channel thereunder, the combination, which comprises wells disposed at opposite ends of said drainage channel positioned beyond the boundary of the basin, a plurality of weirs positioned around said basin communicating with the interior thereof, the throats of said weirs positioned above the upper surface of the aggre- 2. In a trickling filter basin having a relatively large openshallow area adapted to hold a filter aggregate with the upper surface of the aggregate spaced from the upper edge of the basin, and having a false bottom with a centrally disposed drainage channel thereunder, the combination, which comprises wells disposed at opposite ends of said drainage channel positioned beyond the boundary of the basin, a plurality of weirs positioned around said basin communicating with the interior thereof, the throats of said weirs positioned above the upper surface of the aggregate and below the upper edge of the basin, gates in said weirs, catch basins communicating with said weirs, a shear gate in the well at the lower end of said drainage channel, a discharge connection leading from the shear gate, overflow connections from the catch basins to said discharge connection, and valves in said overflow connections.

3. In a trickling filter basin having a relatively large open shallow area adapted to hold a filter aggregate with the upper surface of the aggregate spaced from the upper edge of the basin and having a bottom formed of filter bricks with a centrally disposed drainage channel thereunder, the combination which comprises vertically disposed wells at opposite ends of said drainage channel positioned beyond the periphery of the basin, a plurality of weirs positioned around said basin communicating with the interior thereof, overflow weirs in the sides of the wells, the throats of said weirs positioned above the upper surface of the aggregate and below the upper edge of the basin, gates in said weirs, catch basins communicating with said weirs, a shear gate in the well at the lower end of said drainage channel, a discharge connection leading from the shear gate, overflow connections from the catch basins to the said discharge connections, and valves in said overflow connections.

LUTHER L. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

, UNITED STATES PATENTS Number Name Date 168,191 Slaney -1 Sept. 28, 1875 798,473 Wilson Aug. 29, 1905 813,984 Macnaughton Feb. 27, 1906 944,528 Von Wessely Dec. 28, 1909 1,672,583 Travers June 5, 1928 1,802,726 Levine Apr. 28,1931 2,073,441 Blunk Mar. 9, 1937 2,097,111 'Walker Oct. 26, 1937 2,233,981 Jewell Mar. 4, 1941 2,287,856 Beekhuis, Jr., et al. June 30, 1942' 2,301,025 Friend et a1 Nov. 3, 1942 2,317,782 Levine Apr. 27, 1943 OTHER REFERENCES American Sewerage Practice, vol. 1H, Leonard Metcalf. and Harrison P. Eddy, 3rd edition, published in 1935, McGraw-Hill Book 00., Inc., N. Y. and London. (A copy available in Div. 49.) Pp. 485 and 486 are cited. 

